High frame rate three dimensional ultrasound imager

ABSTRACT

A three dimensional ultrasound imaging device, having an interpolator that creates up sampled ultrasound image information from a three dimensional ultrasound image information using interpolation; and a memory that stores at least one of the three dimensional ultrasound image information and the up sampled ultrasound image information. The three dimensional ultrasound imaging device can have a probe that sends ultrasound waves, gathers reflected ultrasound waves and creates ultrasound information and a processor that converts the ultrasound information to three dimensional ultrasound image information. The ultrasound imaging device may also have a display that displays the up sampled image information. The three dimensional ultrasound imaging device may use at least one of 2 image to 3 image interpolation, 2 image to 4 image interpolation, 3 image to 4 image interpolation and 3 image to 5 image interpolation. The three dimensional ultrasound imaging device may use two dimensional solids and three dimensional volumes. The three dimensional ultrasound imaging device may also create up sampled ultrasound image information that has a greater number of frames, a greater number of three-dimensional frames, a greater number of two-dimensional volumes, a greater number of three dimensional volumes and a larger amount of ultrasound information.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. provisional application Ser.No. 60/430,876 filed Dec. 4, 2002, which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an ultrasound device that produces athree-dimensional image.

2. Description of the Related Art

Ultrasound imaging devices operate by generating ultrasound signals andbouncing the ultrasound signals off an object to generate an image. Theobject may be a fetus or an internal organ such as a heart or kidney.FIG. 1 is a diagram illustrating a general system 100 for generating anultrasound image. A patient 10 needing, for example, ultrasound image oftheir heart has a probe 20 placed against or near their chest. The probe20 produces ultrasound signals and generates a volume of data from thereceived ultrasound signals. This data is sent to imager 50 that thenproduces an ultrasound image on display 90. The image may be saved forlater review and/or may be transmitted to an external storage device.

A disadvantage of a conventional ultrasound system is that it isdifficult to generate a three-dimensional image of sufficient size toeither view the entire heart at once, or to have a frame rate highenough that the image does not appear jerky.

Several solutions have been proposed, such as increasing the processingpower of the ultrasound device, reducing the overall area of thescanning such that the processing complexity drops and the scanning ratecan be increased, image smoothing from frame to frame, and displayingonly two-dimensional images.

However, all of these solutions suffer either extremely large size toproduce the processing power or reduced diagnostic efficiency because ofthe small areas that are actually imaged.

SUMMARY OF THE INVENTION

An increased frame rate can be achieved at various stages in theultrasound imaging process by using for example, interpolation to createthree up sampled images using image data from two detected images. Theup sampled imaged can then have a high frame rate without increasing theamount of scanning information gathered. The invention includes at leasta three dimensional ultrasound device that creates up sampled images,the method of up sampling images for a three dimensional ultrasoundimage and a system for up sampling three dimensional ultrasound imageinformation.

In one exemplary embodiment of the present invention linearinterpolation/up sampling occurs in a three dimensional ultrasounddiagnostic device after a three-dimensional volume has been rendered.The exemplary embodiment thus provides for an apparatus that includes alinear interpolator to an imaging device that also includes a beamformer, detector, 3D scan converter and render engine.

The present invention also provides a method to increase the apparentframe rate in a three dimensional ultrasound diagnostic device,comprising receiving beams, organizing the beams in the planes,detecting 3D scan coordinate system objects, converting the 3D scancoordinate system objects to 3D volumes, interpolating to increase thenumber of volumes, rendering the 3D volumes for display and outputtingthe display information.

In various other exemplary embodiments, the interpolation to increasethe number of volumes can occur at various stages in the process such asduring the acquisition coordinate space; prior to detection of voxel tovoxel; above but post detection (noncoherent); voxel to voxel after scanconversion (typically in Cartesian coordinates); and pixel to pixelafter the volume has been rendered or the tomographic slice has beenextracted from the full volume.

Thus, various exemplary embodiments up sample the number of volumes in a3D xyz domain so that a viewer perceives an increased frame rate. The upsampling is advantageous in a three dimensional environment because ofits computational simplicity and because coherent interpolation islikely to fail for a large number of cases, because the phase for givenvoxel from acquired volume is likely to be uncorrelated with itscorresponding volume in voxel in the next volume.

Thus, exemplary embodiments of the invention include a three dimensionalultrasound imaging device, having an interpolator that creates upsampled ultrasound image information from a three dimensional ultrasoundimage information using interpolation and a memory that stores at leastone of the three dimensional ultrasound image information and the upsampled ultrasound image information. The ultrasound imaging device mayalso include a probe that sends ultrasound waves, gathers reflectedultrasound waves and creates ultrasound information and a processor thatconverts the ultrasound information to three dimensional ultrasoundimage information. The ultrasound imaging device of may also have adisplay that displays the up sampled image information.

The ultrasound imaging device in several embodiments has theinterpolation that is at least one of 2 image to 3 image interpolation,2 image to 4 image interpolation, 3 image to 4 image interpolation and 3image to 5 image interpolation. The ultrasound imaging device may act onthree-dimensional information, two dimensional planes and threedimensional volumes. The ultrasound imaging device may also have the upsampled ultrasound image information that has at least one of a greaternumber of frames, a greater number of three-dimensional frames, agreater number of two-dimensional planes, a greater number of threedimensional volumes and a larger amount of ultrasound information.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of the invention will become apparent and more readilyappreciated for the following description of the preferred embodimentstaken in conjunction with the accompanying drawings of which:

FIG. 1 illustrates a general ultrasound system;

FIG. 2 is an exemplary ultrasound apparatus according to the invention;

FIG. 3 is a flow chart illustrating a method of producing a high framerate 3D ultrasound image according to the invention;

FIG. 4 is another flow chart illustrating a method of producing a highframe rate 3D ultrasound image according to the invention;

FIG. 5 is an exemplary embodiment of the data that is handled at variousstages in the production of a three dimensional ultrasound image;

FIG. 6 is another exemplary embodiment of the data that is handled atvarious stages in the production of a three dimensional ultrasoundimage;

FIG. 7 is a third exemplary embodiment of the data that is handled atvarious stages in the production of a three dimensional ultrasoundimage;

FIG. 8 is an exemplary embodiment of a method for up sampling ultrasoundimage data; and

FIG. 9 is another exemplary embodiment of a method for up samplingultrasound data.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the exemplary embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to the like elementsthroughout.

The present invention creates a new, much higher frame frequency rateultrasound device as can be seen in the general system diagram ofFIG. 1. In FIG. 1, the patient 10 is having an ultrasound image taken ofhis heart using ultrasound system 100. Ultrasound system 100 includesprobe 20, imager 50 and display 90.

The probe 20 emits ultrasound waves, which differentially bounce off apatient's heart and return to the probe 20. Ultrasound waves arereflected differentially depending on the density of an object. Theprobe 20 is connected to the imager 50. The imager 50 converts the datasent from the probe 20 of the ultrasound wave of the patient's 10 heart.The imager sends the data to the display 90. The display 90 can displayan ultrasound image of the patient's heart.

Ultrasound waves are useful for many different applications, such asimaging hearts, fetuses and other portions of a human's anatomy. Inaddition, the system can be used to image any other material containingdifferential responses to ultrasound waves, such as metal, welds, or anyother now know or later devised material.

FIG. 2 is an exemplary block diagram of an ultrasound-imaging device ofthe present invention. The ultrasound-imaging device has a probe 120,user input device 130, imager 150 and display 190. The probe 120 cancontain a beam transmitter 122 and beam receiver 124. The beamtransmitter 122 can be in a now known or later device apparatus fortransmitting waves with a differential rate of reflection depending onthe device to be inspected. The beam receiver 124 can be in a now knownor later device that can receive the waves transmitted. The probe 120can then translate the received information in the form of reflectedwaves and convert it into a transportable form for transmission to theimager 150.

User input device 130 can be a keyboard, a mouse, a light tablet or anyother device for allowing the user to input and control the probe, theimager, or the display. Imager 150 can contain input 152, beam former154, detector 156, 3D scan converter 158, render engine 160, output 162,interpolator 164, processor 166, controller 168, and memory 170. Imager150 operates by receiving signals that correspond to the reflection ofthe waves received by the beam receiver 124 at input 152. The controller168 can then direct the information to memory 170, interpolator 164 orbeam former 154.

Other exemplary embodiments of three dimensional ultrasound devices caninclude additional modules, or combine several of the modules into one.For example, the beam former 154, detector 156, 3D scan converter 158,render engine 160 can be programs stored in memory 170 that are used toset a programmable processor 166 to perform the functions of beam former154, detector 156, 3D scan converter 158 and render engine 160. Each ofthe beam former 154, detector 156, 3D scan converter 158, render engine160 will be explained functionally in relation to a relatedthree-dimensional ultrasound-imaging device.

A related three-dimensional ultrasound-imaging device uses standardprocessing steps. The first standardized processing step is to organizethe received raw data into two-dimensional planes, called beam forming.The two-dimensional planes are then analyzed to detect 3D scancoordinates, called detecting. The 3D scan coordinates can then beaggregated to form 3D volumes, called 3D scan converting and the 3Dvolumes can then be rendered to be output on the display terminal.

The beam former 154 can thereby be used to form the beams intothree-dimensional coordinates of information. The detector 156 can thenbe used to detect objects within the planes. The 3D scan converter 158can then be used to convert the objects detected by detector 156 intothree-dimensional objects. The render engine 160 can then be used torender the three-dimensional objects created by the 3D scan converter158 into display data. The display data can then be output to output 162and transferred to display 190 where the results are displayed.

3D scan coordinates can be a probe-centric coordinate system win whichthe data is stored in three dimensions related to the location of theprobe. The three dimensions can be “r,” the radial distance, sometime inCentimeters, from a body-target to a center of the probe face, “theta,”the azimuth or lateral angel in degrees left or right from the center ofthe probe, and “phi,” the elevation angle in degrees up or down from thecenter of the probe. 3D scan conversion can then be the converting theimage information stored in 3D scan coordinates to another 3D data set,for example a Cartesian coordinate system, that can consist of X, Y andZ coordinates.

As noted above, beam former 154, detector 156, 3D scan converter 158,and render engine 160 can either be application specific integratedcircuits, or programs to be implemented on processor 166. Controller 168can control the flow of information from the input 152 to the output 162and control the various steps in between. Memory 170 can be RAM, ROM, ahard drive or any other now known or later device means for storing dataon either a temporary or permanent basis.

Interpolator 164 is a straight-line interpolator that forms one of manydifferent types of average images from raw data. For example, a firstframe of data may be entered into memory 170 and a second frame of datamay be entered into memory 170. Interpolator 164 may then be used tocreate a third frame of data that is the average of the first two framesof data saved in memory 170. The interpolation can happen at any ofseveral stages in the standardized process for creating athree-dimensional image.

The pre-scan coordinate system can vary as a function of variousexemplary probe types used in various exemplary embodiments. Apolar/spherical coordinate system is most applicable to a “sector”embodiment, which tends to scan the body using a windshield wiper fansweep. An “Omni-Tee” probe is one exemplary embodiment of a probe usinga cylindrical coordinate system. Other exemplary embodiments might scanthe body using a parallelogram coordinate system.

Another exemplary embodiment of the invention can use a beam former thatthat scans in a spiral format, where the beams cannot be aligned along atraditional planar format. The invention is applicable regardless of themethod of acquiring and analyzing the ultrasonic beams. Conversion canbe used in various exemplary embodiments to facilitate “down stream”volume rendering. However, it is possible in other exemplary embodimentsto render directly from raw, unconverted data sets.

A possible exemplary embodiment can take any 2 of the 3 polar dimensionsand perform two dimensional scan conversion, resulting in a twodimensional plane of information for each value of the third dimension.The thereby created stack of two dimensional planes can then be threedimensionally converted to a three dimensional Cartesian coordinatesystem.

FIG. 3 is a flow chart of an exemplary process of applying theinvention. The process starts at start 200 and continues to receivebeams 210. In receive beams 210, reflected ultrasound frequency beamsare received by the process as raw data. The method then continues toorganize beams into planes 220.

Organize beams into planes 220 is where the raw data is organized intotwo-dimensional planes. The process then continues to detect 3D scancoordinates 230. In detect 3D scan coordinates 230, the planes of dataare then analyzed to detect any 3D scan coordinates that may existwithin the data. The process then continues to convert 3D scancoordinates to 3D volumes 240. In convert 3D scan coordinates to 3Dvolumes 240, the process organizes a series of 3D scan coordinates andconverts them into 3D volumes. The process then continues to interpolateto increase the number of volumes 250.

In interpolate to increase the number of volumes 250, an interpolatorcan do a straight-line interpolation of the three-dimensional volumesacross various iterations of the data in the time dimension. Thus, morethree-dimensional volumes are created than were originally detected inthe time realm. Thus, an increased frame rate can be displayed. Themethod then continues to render 3D volumes for display 260.

In render 3D volumes for display 260, the three-dimensional volumes arerendered for display on the display panel. The method then continues tooutput display information 270. An output display information 270, therender three-dimensional volumes are output to the display device. Themethod then continues to the determination of repeating 280. Indetermination of repeat 280, if the method is to continue the methodjumps back to receive beams 210. If the method is to conclude the methodcontinues to end 290.

FIG. 4 is a flow chart of another exemplary process of applying theinvention. The process starts at start 300 and continues to receivebeams 310. In receive beams 310, reflected ultrasound frequency beamsare received by the process as raw data. The method then continues toorganize beams into planes 320.

Organize beams into planes 320 is where the raw data is organized intotwo-dimensional planes. The process then continues to detect 3D scancoordinates 330. In detect 3D scan coordinates 330, the planes of dataare then analyzed to detect any 3D scan coordinates that may existwithin the data. The process then continues to interpolate to increasethe number of volumes 340.

In interpolate to increase the number of volumes 340, an interpolatorcan do a straight-line interpolation of the two-dimensional volumesacross various iterations of the data in the time dimension. Thus, moretwo-dimensional volumes are created than were originally detected in thetime realm. Thus, an increased frame rate can be displayed. The processthen continues to convert 3D scan coordinates to 3D volumes 350. Inconvert 3D scan coordinates to 3D volumes 350, the process organizes theseries of 3D scan coordinates and converts them into 3D volumes. Themethod then continues to render 3D volumes for display 360.

In render 3D volumes for display 360, the three-dimensional volumes arerendered for display on the display panel. The method then continues tooutput display information 370. An output display information 370, therender three-dimensional volumes are output to the display device. Themethod then continues to the determination of repeating 380. Indetermination of repeat 380, if the method is to continue the methodjumps back to receive beams 310. If the method is to conclude the methodcontinues to end 390.

FIG. 5 is a block diagram showing the data in the process of producing athree-dimensional ultrasound image. The process begins with acquiringimages A 410, image B 430 and image C 450 from the raw ultrasound wavesthat are returned to the ultrasound receiver. The raw data images A 410,image B 430 and image C 450 can be saved in a memory and retrieved atlater periods of time.

Next, 2D images can be detected such as images 412, images 432 andimages 452. The images then represent two-dimensional slices of theobject at an angle, position and time period. The two-dimensional imagescan then be converted into three-dimensional images to give a block ofthree-dimensional images A414, a block of three-dimensional images B434and a block of three-dimensional images C454.

Interpolation can then occur. The interpolation can be any one ofseveral types. The first exemplary type of interpolation is the imageitself A 460, half of the image A combined with one half of image B 462,then image B 464. The images can then be rendered to come up with imageA460, half image A, plus half image B462, image B464, half image B, plushalf image C466 and image C468. Thus, with very little additionalcomputational complexity, a three-dimensional ultrasound device canproduce a high frame rate ultrasound image.

FIG. 6 is another block diagram showing the data in the process ofproducing a three-dimensional ultrasound image. The process begins withacquiring images A 500, image B 530 and image C 550 from the rawultrasound waves that are returned to the ultrasound receiver. The rawdata images A 510, image B 530 and image C 550 can be saved in a memoryand retrieved at later periods of time.

Next, 2D images can be detected such as images 512, images 532 andimages 552. The images then represent two-dimensional slices of theobject at an angle, position and time period. Interpolation can thenoccur. The interpolation can be any one of several types. The firstexemplary type of interpolation is the image itself A 570, half of theimage A combined with one half of image B 572, then image B 574.

The images can then be converted into three-dimensional images to comeup with image A570, half image A, plus half image B572, image B574, halfimage B, plus half image C576 and image C578. Thus, with very littleadditional computational complexity, a three-dimensional ultrasounddevice can produce a high frame rate ultrasound image. Thethree-dimensional images can then be rendered to give a block ofthree-dimensional images 560, 562, 564, 566 and 568.

FIG. 7 is a block diagram showing the data in the process of producing athree-dimensional ultrasound image. The process begins with acquiringimages A 610, image B 630 and image C 650 from the raw ultrasound wavesthat are returned to the ultrasound receiver. The raw data images A 610,image B 630 and image C 650 can be saved in a memory and retrieved atlater periods of time.

Interpolation can then occur. The interpolation can be any one ofseveral types. The first exemplary type of interpolation is the imageitself A 680, half of the image A combined with one half of image B 682,then image B 684. The images can then be rendered to come up with imageA 680, half image A, plus half image B 682, image B 684, half image B,plus half image C 686 and image C 688.

Next, 2D images can be detected such as images 680, images 682, images684, images 686 and images 688. The images then representtwo-dimensional slices of the object at an angle, position and timeperiod. The two-dimensional images can then be converted intothree-dimensional images to give a block of three-dimensional images A670, a block of three-dimensional images half image A, plus half image B672, a block of three-dimensional images B 674, a block ofthree-dimensional images half image B, plus half image C 676 and a blockof three-dimensional images C678.

The images can then be rendered, producing images 660, 662, 664, 666 and668. Thus, with very little additional computational complexity, athree-dimensional ultrasound device can produce a high frame rateultrasound image. Thus, a lower error rate involved with interpolationearly in the process can be balanced by additional complexity involvedin handling a larger number of images.

FIG. 8 is an exemplary embodiment of a second type of interpolation thatmay be used. In FIG. 8, three-dimensional image A 710, three-dimensionalimage B 720 and three-dimensional image C 730 can be interpolated into3-quarters image A plus 1-quarter image B 780, 1-quarter image A plus3-quarters image B 782, and 3-quarters image B plus 1-quarter image C784 and 1-quarter image B and 3-quarters image C 786.

FIG. 9 is another exemplary embodiment of a type of interpolation thatmay be used. In FIG. 9, three-dimensional image 810 andthree-dimensional image C820 can be interpolated into ⅞ image A plus ⅛image B 880, ⅝ image A plus ⅜ image B 882, ⅜ image A plus ⅝ image B 884and ⅛ image A plus ⅞ image B 886.

Thus, as can be seen in FIGS. 8 and 9, various other interpolationschemes may be used, as is well known in the art. Various exemplaryembodiments have been shown that include differing numbers of beginningand ending frames. Various additional exemplary embodiments includegreater or lesser numbers of beginning frames and greater or lessernumbers of ending frames. In addition, the exemplary interpolation hasbeen shown where only two frames are interpolated into the additionalframes desired. Additional numbers of frames can be used to produce theinterpolated information.

The exemplary embodiments shown also use straight-line interpolation.Various other exemplary embodiments may use various other forms ofinterpolation such as parabolic, stepped, cubic, FIR (Finite ImpulseResponse, IIR (Infinite Impulse Response), or other formulaic methods ofinterpolation.

Thus a person of ordinary skill in the art can appreciate that thepresent invention may be applied to any type of ultrasound device.Further, the present invention may be retrofitted onto existingultrasound devices and may expand the number of uses for an ultrasounddevice because of the additional utility.

Although preferred embodiments of the present invention have been shownand described, it would be appreciated by those skilled in the art thatchanges may be made in this embodiment without departing from theprinciples and spirit of the invention, the scope of which is defined inthe claims, drawings and their equivalents.

1. A three dimensional ultrasound imaging device, comprising: aninterpolator that interpolates three-dimensional ultrasound image datacorresponding to at least two sequential detected images in an imagedata stream to obtain at least one interpolated three-dimensionalvolume, providing up sampled three-dimensional volumes in a timedimension for increasing frame rate.
 2. The ultrasound imaging device ofclaim 1, further comprising: a probe that sends ultrasound waves,gathers reflected ultrasound waves and creates the ultrasound imagedata; and a processor that converts the ultrasound image data to thethree-dimensional volumes.
 3. The ultrasound imaging device of claim 1,further comprising: a display that displays the up sampledthree-dimensional volumes.
 4. The ultrasound imaging device of claim 1,wherein the interpolation comprises at least one of interpolatingultrasound-image data corresponding to 2 sequential detected images to 4three-dimensional volumes, interpolating ultrasound-image datacorresponding to 3 sequential detected images to 4 three-dimensionalvolumes and interpolating ultrasound-image data corresponding to 3sequential detected images to 5 three-dimensional volumes.
 5. Theultrasound imaging device of claim 1, wherein the interpolationcomprises at least one of straight line, parabolic, stepped, cubic, FIR(Finite Impulse Response) and IIR (Infinite Impulse Response)interpolation.
 6. The ultrasound imaging device of claim 1, wherein theinterpolation comprises interpolating ultrasound-image datacorresponding to 2 sequential detected images to 3 three-dimensionalvolumes.
 7. A method of processing ultrasound imaging data, comprising:creating up sampled ultrasound image three-dimensional volumes in a timedimension from a plurality of three-dimensional volumes usinginterpolation; storing at least one of the three-dimensional volumes andthe up sampled ultrasound image three-dimensional volumes; and renderingthe up sampled ultrasound image three-dimensional volumes into displaydata, wherein creating the up sampled ultrasound image three-dimensionalvolumes comprises interpolating three-dimensional ultrasound image datacorresponding to at least two sequential detected images to obtain atleast one interpolated three-dimensional volume.
 8. The method ofprocessing ultrasound imaging data of claim 7, further comprising:sending ultrasound waves, gathering reflected ultrasound waves andcreating raw ultrasound data; and converting the raw ultrasound data tothe plurality of three-dimensional volumes.
 9. The method of processingultrasound imaging data of claim 7, further comprising: displaying therendered display data.
 10. The method of processing ultrasound imagingdata of claim 7, wherein interpolating the plurality ofthree-dimensional volumes comprises at least one of interpolatingultrasound-image data corresponding to 2 sequential detected images to 4three-dimensional volumes, interpolating ultrasound-image datacorresponding to 3 sequential detected images to 4 three-dimensionalvolumes and interpolating ultrasound-image data corresponding to 3sequential detected images to 5 three-dimensional volumes.
 11. Themethod of processing ultrasound imaging data of claim 7, whereininterpolating the plurality of three-dimensional volumes comprises atleast one of straight line, parabolic, stepped, cubic, FIR (FiniteImpulse Response) and IIR (Infinite Impulse Response) interpolation. 12.The method of processing ultrasound imaging data of claim 7, whereininterpolating the plurality of three-dimensional volumes comprisesinterpolating ultrasound-image data corresponding to 2 sequentialdetected images to 3 three-dimensional volumes.
 13. A system forthree-dimensional ultrasound imaging, comprising: an interpolator thatinterpolates three-dimensional coordinates of ultrasound image datacorresponding to at least two sequential detected images in an imagedata stream to obtain at least one interpolated three-dimensionalobject, providing up sampled three-dimensional objects in a timedimension for an increased frame rate; and a memory that stores at leastone of the three-dimensional ultrasound image data and the up sampledthree-dimensional objects.
 14. The system for three-dimensionalultrasound imaging of claim 13, further comprising: a probe that sendsultrasound waves, gathers reflected ultrasound waves and creates theultrasound image data; and a processor that converts the ultrasoundimage data to the three-dimensional coordinates.
 15. The system forthree-dimensional ultrasound imaging of claim 13, further comprising: arender engine that renders display data from the up sampledthree-dimensional objects; and a display device that displays therendered display data.
 16. The system for three-dimensional ultrasoundimaging of claim 13, wherein the interpolation comprises at least one ofinterpolating three-dimensional coordinates corresponding to 2sequential detected images to 4 three-dimensional objects, interpolatingthree-dimensional coordinates corresponding to 3 sequential detectedimages to 4 three-dimensional objects and interpolatingthree-dimensional coordinates corresponding to 3 sequential detectedimages to 5 three-dimensional objects.
 17. The system forthree-dimensional ultrasound imaging of claim 13, wherein theinterpolation comprises at least one of straight line, parabolic,stepped, cubic, FIR (Finite Impulse Response) and IIR (Infinite ImpulseResponse) interpolation.
 18. The system for three-dimensional ultrasoundimaging of claim 13, wherein the interpolation comprises interpolatingthree-dimensional coordinates corresponding to 2 sequential detectedimages to 3 three-dimensional objects.